Tank for settling, filtering, and collecting solids from liquids.



J. E. ROTHWELL. TANK FOR SETTLINGfFII-TERING, AND COLLECTING SOLIDS FROM LIQUIDS. APPLICATION FILED JUNE 17, 1909.

976,923. Patented Nov. 29, 1910.

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UNITED STATES PATENT OFFICE.

JOHN EDWARD ROTHWELL, 01? DENVER, COLORADO, ASSIGNOR TO COLORADOTRON WORKS COMPANY, OF DENVER, COLORADO.

TANK FOR SET-TLING, FILTERING, AND COLLECTING SOLIDS FROM LIQUIDS.

' specification.

- tank wall.

My. invention relates to plants for the treatment of ore and particularly to an apparatus for the separation of liquid and solids, so that either one or both may be subjected to a subsequent treatment when so separated. In such plants in which a part of the operation is performed by the wet process, as with water or a cyanid solution, it is sometimes necessary to reduce the ratio of liquid and solid, so that either or both may be in proper condition for further treatment, and my invention is designed to provide an apparatus forthis purpose.

The invention consists in the features and combination and arrangement of parts here after described and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a plan view of the apparatus with a portion of the baffle plates broken away to show the lower structure; Fig. 2 is a central vertical sectional view of the invention. 'Fig. 3 is a detail view.

The apparatuscomprises a tank A intov which the liquid containing the solids is fed continuously at one end, at a point some distance below the top, and is' caused to pass to the other end of the tank, the separation of the solids from the liquid taking place during the time the liquid is moving from the inlet end to the discharge end of the tank, the solids settling to the bottom, the clear liquid overflowing an adjustable weir at the discharge end of the tank. The tank is preferably rectangular in form. At its feed end it is provided with a feed box B, the inlet B from which into the tank is located about midway the height of the tank, at which point perforations are made in the The liquid bearing the solids passing through these perforations enters first a settling chamber M formed between the end wall of the tank and the diaphragm or partition D arranged vertically and terminating at its upper edge slightly below Specification of Letters Patent. Patented N 29, 191() Application filed June 17, 1909. Serial No. 502,739. V

the .top edge of the tank to allow for the flow of the liquid thereover into the main body of the tank. \Vhile the upper part of this partition is solid, the lower part is perforatedat N. Below the settling chamber M is a collecting receptacle G tapering downwardly and provided at its'lower end with a gate or valve Z. The larger upper end of the collecting receptacle communicates freely with the settling chamber M on one sidev of the partition D, and with the main chamber of the tank on the other side of the said partition. Within the main chamber of the tank battle plates E extend across at an angle of about 60 or at the desired inclination to prevent solids which settle thereon from adhering thereto. The topedges of the bafiie plates lie in a horizontal plane slightly below the top of the tank, and the lower edges in a plane about onehalf'the depth of the tank.

Transverse partitions F subdivide the bottom of the tank into independent sections, containing a filtering material, and in each of said sections a perforated pipe F is placed, which passes through the side of tank at the bottom, and 'to the outer endof which are attached suitable valves and fittings. The pipe F isperforated withsmall apertures along its length for collecting the filtrate and also to permit of reversing the flow for washing the filtering media X in the separate compartments formed by the partitions.

A double chain scraper conveyer G is submerged at the bottom of the tank and passes around the sprocket wheels G so that the seraperfiights G move along the surface of the filter media toward the collecting receptacle C. The upper part of the chains and scraper returns over the top of the wheels toward the overflow end of the tank,

and the chains are supported on flanges or shelves Gr attached to the sides of the tank. The speed of this chain traveling from end to end of the tank is very slow, in practice, about 2 lineal feet per minute, and therefore it does not have a tendency to agitate the solids settling to the surface of the filter. A suitable mechanism G is used to operate the scraper conveyer.

An adjustable weir H is located atthe overflow end of the tank, arranged to raise andlower mechanically, such as with rods and hand wheel, in order to regulate the height of the liquid standing in the tank above the baffle plates; 1

An overflow launder J for theclear liquid or solution, freed from solids, is located across the end of the tank, and collects the liquid overflowing the weir and delivers it through'the opening'K to any desired pointfor after treatment. 4

The operation of this apparatus is as follow The fine solid matter suspended in a large proportion of liquid is delivered to the feed box at B and passes into the tank through the small apertures shown at B; the tendency of these small openings is to distribute the material passing through over a larger area; after passing these openings pass through the. perforations at N andmove'along the length of the tank below'the I bafiies, and gradually settle onto the filter surface, and are gently moved back to the receptacle 0 by the scraper conveyer. The inclined baflies are used to retard the flow of the lighter solids and provide a space free fie from agitating currents. For instance, the

liquid carrying the fine solids flows slowly over the top of the battle plates, and any sol Ids that have settled below th'e'top edge of the baflie plate are retained in that section and settles down along the upper surfaceof the baifle, undisturbed the displacement -occurring by the settlement of this solid rises along the underside of the'adjacent inclined baffle plate. Another function of the inclined baffle is to practically increase the settling area of the tank. a

The filter isdesigned to increase the working capacity of the tank. The whole of the liquid entering the tank can be drawn through the filter, if desired, thus assisting the settling quality of the .solids,or the overflow weir can be raised to a height to prevent the discharge of liquid at this point except as a means to prevent the overflowing D of the tank.

-- partments, each with its own perforated 69 pipe, isto permit "of each separate filter The filter bed is inclined upwardly from the feed end toward the overflow end, in

order to get a deeper bedof filtering media. where the finer solids will settle.

v The subdlvision'of the filter bed into separate comsection being operated independently and to beable to wash or cleanse the filtering media by reversingthe flow of liquid through the .perforatedpipe. Thus in'practice the fine solids settle in a compact mass on the surface of the filteringmedia and becomes practically impervious. When this occurs the outlet valve of the perforated pipe is closed and an inflow valve opened, permitting a flow of liquid or air back through the pipe and upward through the filtering media. This upward current lifts the compact mass of fine. settled pulp from the surface of the media and themovement of the'scrapers of the submerged conveyer carries the solid to I the discharge end and collecting receptacle.

The collecting receptacle is conical or pyramidal in form. The gate Z is to permit the control of the flow therefrom continuously or intermittently, as the-after treatment. I

Fig. 3 shows on inflow valve at F one of required by these being in connection with each perforated pipe'F in the bottom of the filter bed, to which valve any suitable hose connection may be made to induct an air 'or liquid into the pipeF for washing the filter medium X. F isa valve to control the outflow. of the filtrate, and Y is a launder. In operation the filtrate will. be drawn. through the valves F until the filter medium becomes clogged and the flow reduced, then the valve F will be closed and a hose attached to the valve'F and the cleansing liquid or air admitted to the pipe F, and this action may be carried out in connection with all of the pipes when necessary.

I claim as my invent1on: I

1. 'In combination with a settling tank, a perforated partition near the feed end thereof for retarding and distrtibuting the "mixture of solids and liquid to be separated,

said partition having an overflow at its top,

substantially as described.

2. In combination with a settling tank a partition formlng a settling chamber and a collectin I I eating with said'settling chamber, said partition having an overflow, and a conveyer operating in the main part of the tank to. deliver the solids to the collecting receptacle, substantially as described.-

3. In combination with a settlin tank, a partition forminga settling cham er near the feed end having an underflow and an overflow, a collecting receptacle conimuni:

the main chamber of tie tank, and a conveyer in the main chamber to deliver the solids to the collecting receptacle, substantially as described. I

4. In combination with a settling tank, baflles therein at the upper. part thereof, means for maintaining a water level at or near the. top of the said baflies, and inlet means for the mixed liquid and solid at a point below the water level, substantially as described.

5. In combination in a settling tank, a partition near the inlet end having a perforated lower part and an imperforate upper receptacle below and communi eating with said settlin chamber and with part terminating below the top of the tank to permit the lighter material and liquid to pass thereover, battles at the upper part of the main chamber of the tank, a scraping conveyer operating along the bottom of the tank and a collecting receptacle communicating with he main tank and with the set tling chamber formed by the said partition, substantially as described.

6. In combination in a settling tank, a partition near the inlet end having a perforated lower part and an imperforate upper part terminating below the top of the tank, and conveying means at the bottom of the tank, substantially as described.

7 A settling tank having an inlet at one end and an outlet at the other, and a series of battle plates arranged at the top of the tank in inclined position and slightly below the outlet to allow overflow at their top, all of said battles being above the bottom of the tank with a free space beneath them from end to end of the tank, substantially as described.

8. In combination with a settling tank, a series of baffle plates at the upper part thereof inclining upwardly and in a direction from the inlet to the outlet end of the tank, and submerged for overflow, all of said baflle plates being above the bottom of the tank with a free space beneath them from end to end of the tank, substantially as described.

9. A settling tank having an inlet at one end and an outlet at the other between which the liquid flows substantially horizontally, and a series of battles in the upper part of the tank below the surface of and in the course of the flow of the liquid, said baflies having a free space beneath them from end to end of the tank, substantially as described.

10. A settling tank having an inlet at one end and an outlet at the other between which the liquid flows substantially horizontally, and a series of battles in the upper part of the tank in the course of the flow of the liquid, a collecting receptacle near the inletend of the tank and a conveyer at the bottom of the tank for moving the settled material from the outlet end of the tank to the collecting receptacle, substantially as described.

11. A settling tank having a series of compartments along its bottom containing filtering material and a perforated pipe in each compartment for draining off the.filtrate 'or for washing the filtering material, substantially as described.

12. In combination in a settling tank,,a filter bed at the bottom thereof and a scraper conveyer operating thereover, substantially as described.

13. A settling tank having a filter bed with a pipe or pipes embedded therein for stantially as described.

washing the filtering medium, and a scraper moving over the filter bed, substantially as described.

14. A settling tank having a horizontal flow from inlet to outlet, baflle plates at the top of the tank in the'course of said flow, and an adjustable weir atthe discharge end of the tank, substantially as described.

15. A settling tank having a vertical part-ition'near the inlet end with a perforated lower part and an imperforate upper part terminating below the top of the tank for the overflow of the lighter material, and a conveyer at the lower part of the tank, sub- 16; A settling tank having a substantially vertical partition at one end forming a settling chamber between itself and the wall of the tank, the lower part being perforated and the upper part imperforate, and terminating at a point below the top of the tank, a collecting chamber below the settlingchamher, and communicating therewith and also with the .main tank, said settling and col-' lecting chambers being at the inlet end of the tank, substantially as described.

17 A settlingtank having an inlet and an outlet between which the material passes substantially horizontally, an inclined filter bed inclining upwardly from the inlet toward the outlet end of the tank, and a conveyer moving over said filter bed, substantially as described.

18. A settling tank having a filter bed divided up into sections with dividing walls between, and pipes in said sections, substantially as described.

19. In combination the settling tank, baflles therein, and outlets distributed over the bottom for drawing ofi the liquid at different points, and a conveyer at the bottom of the tank, substantially as described.

20. In combination a settling tank having an inlet at one-end and an outlet at the other end, porous material at the bottom, said material being subdivided into a number of separate transverse compartments, and anoutlet from each individual compartment for drawing off the liquid, and valves for controlling the said outlets, substantially as described.

21. In combination, a settlingitank, a

filter bed at the bottom thereof, outlets for drawing oif the liquid at different points through the said bed, and a conveyer, substantially as described. i

' 22. In combination in a settling tank, a partition near the inlet having an overflow and an underflow, and forming a settling chamber, a collecting receptacle communicating with boththe settling chamber and with the main part of the tank, and a conveyer at the bottom of the tank, substantially as described.

23. In combination in a settllng tank, a

vertical partition near the inlet having an upper inperforate portion and a l0wer'perforat-ed portion, said partition being submer ed-for the flow of the material over its upper edge, and a collecting chamber com- ..municating with the main part of the tank andwith the (portion divided ofl" therefrom by the said partition, the inlet to the tank being substantially midway of-the hei ht thereof and ofthe partition, substantia y v as described. I Y

24. In combination a tank having an inlet at about niidway of its height at one' 

